In 1909, young William F. Buckley Sr. (1881-1958), who grew up in the dusty South Texas town of San Diego, graduated from the University of Texas law school and headed for Mexico City. Fluent in Spanish, familiar with Mexican traditions, and soon fit to practice law south of the border, Buckley was headed up the aisle to vast wealth and cultural power. On the way, he took a front-row seat at the Mexican Revolution and played a key role in steering...